A friend mentioned recently how he missed learning, the kind of learning you’d get in a college atmosphere. The main culprit was lack of disposable funds.

If it’s more money than time that’s making going back to school difficult, or you just want to get ahead on your day job or the job you wish you had, here are four online options to increase your knowledge and skills:

1. “Take the world’s best courses, online, for free.” To date, Coursera.org has 554 courses that include the arts, business management, computer science, humanities, law, medicine, and teacher professional development. Want to learn to write like Mozart? Get started on the 6-week course. Concerned about globalization affecting us personally and economically? Register for the 10-week course. I haven’t taken a Coursera course yet but I’ve got this site bookmarked.

2. “Webinars and videos for professionals and their communities.” I’ve attended many free Brighttalk webinars since I discovered them back when I was unemployed. My focus was learning about social media, but Brighttalk’s communities of learning include accounting, healthcare, human resources, and sales. Also, once you’ve signed up for a webinar, it remains in your account so you can watch it again.

3. “Free webinars and online events, both live and on-demand.” Webex.com’s Channels cover topics such as arts & culture, communication & media, education, leadership, personal growth, and science & technology. I’ve used Webex in the past for company-sponsored events, so some of these webinars won’t be free, but it could be worth finding the ones that are.

4. “Share what you know and love through presentations, infographics, documents and more.” Slideshare is a haven for finding out how other people have solved knotty problems or discovered a cool new way to look at their everyday jobs. I’ve used this for social media purposes, but I see categories such as business & management, career, design, and technology.

What free or relatively inexpensive online courses or webinars do you use?